In the company's Dev Center web site under the "Naming your app" page, Microsoft says specifically: "Make sure your app name doesn't include the word metro. Apps with a name that includes the word metro will fail certification and won't be listed in the Windows Store."

As we have reported before, Microsoft is ditching the use of the "Metro" brand for the Windows 8 user interface, reportedly due to a trademark dispute with another company. The "Naming your app" page indicates it was updated on Tuesday, August 14th but there's no concrete word if the "Metro" name ban was put in place on that date or if it has been a part of that page all along.

Users of the Release Preview version of Windows 8 know that the popular Twitter app MetroTwit launched a Windows 8 port in late June. It would seem like Microsoft would not have allowed that app to be released if their "Metro" name banning policy was in place before now. In a Twitter message today, Long Zheng, the product manager of MetroTwit, stated, "... the rule is if you can't have an app that infringes someone else's trademark. There is no fact to indicate we are."